RADICAL PHOTOPOLYMERIZATION OF NOVEL PERFLUOROPOLYALKYLETHERS (PFPAEs)

Fluoropolymers are currently used in many high technology areas such as aerospace, aeronautic (seals, gaskets), automotive industry, microelectronics, optics (core, claddings of optical fibers) or even for antifouling and release coatings or textile treatment. Thanks to the fluorine atoms, these polymers particularly demonstrate high chemical and thermal inertness, low flammability, refractive index and surface energy and excellent ageing and weather resistances.1 However, safety concerns were highlighted for long perfluoroalkyl chains leading to their banning.2 Perfluoropolyalkylethers (PFPAEs) based on structural units such as –(CF2O)–, –(CF2CF2O)–, –(CF2CF2CF2O)– and –(CF(CF3)CF2O)– are an interesting non-toxic alternative.3 Besides, they are not crystalline and showed a stability from -100°C and 400°C at the liquid state. 4 The purpose of our work is to synthesize new PFPAE precursors by anionic ring-opening polymerization. They can then be functionalized with photo-curable substituents ((meth)acrylate5-7, maleate, fumarate, maleimide, vinyl ether). The present work describes the synthesis and photopolymerization of macromonomers from monofunctional PFPAE precursors of different molecular weight (Mw = 1250, 2000 g/mol). An optimization of the synthesis ways of the various fluorinated oligomeric macromonomers was firstly required on monofunctional materials. It allowed a better understanding of the reactivity of the fluorinated precursors and a minimization of the presence of side-reactions. The first results of the photopolymerization of maleimides without photoinitiator will be discussed highlighting some interesting features such as the presence of air, the absence or presence of PFPAE vinyl ether.